高层建筑作为应对城市人口和经济增长的重要手段,是世界性城市发展的必然趋势之一。高层建筑的空间分布与高度控制对城市景观有显著影响,是城市景观控制的重要方面。本文以伦敦市为例,总结了高层建筑控制相关政策的发展历程,并从区域控...高层建筑作为应对城市人口和经济增长的重要手段,是世界性城市发展的必然趋势之一。高层建筑的空间分布与高度控制对城市景观有显著影响,是城市景观控制的重要方面。本文以伦敦市为例,总结了高层建筑控制相关政策的发展历程,并从区域控制、天际轮廓线和景观保护区三个方面详细介绍了高层建筑的控制内容和方法,同时以让·努维尔(Jean Nouvel)设计的新交易港一号(One New Change)商场为例进一步说明。最后,文章讨论了英国城市景观中的高层建筑控制对我国的启示。展开更多
Multimodal control for seismic responses of tall buildings is performed by using MTMDs. Installation and main parameters of MTMDs are described, equations of motion of the coupled system of tall buildings and MTMDs ar...Multimodal control for seismic responses of tall buildings is performed by using MTMDs. Installation and main parameters of MTMDs are described, equations of motion of the coupled system of tall buildings and MTMDs are built under earthquake excitations, and parametrical optimization for multimodal control is carried out under excitations of harmonic ground motion. An 11 story frame building controlled by MTMDs is simulated under the excitation of El Centro earthquake (1940, NS), and its displacement response at the top floor in the case of multimodal control is reduced by 20% more than the case of single modal control. Some conclusions are given as the MTMDs is an effective, reliable and practical passive measurement for controlling seismic responses of tall buildings and the multimodal control has better adaptability and reliability by comparison with the single modal control.展开更多
Most of modern tall buildings using lighter construction materials with high strength and less stiffness are more flexible, which occurs excessive wind-induced vibration, resulting in occupant discomfort and structura...Most of modern tall buildings using lighter construction materials with high strength and less stiffness are more flexible, which occurs excessive wind-induced vibration, resulting in occupant discomfort and structural unsafety. It is necessary to predict wind-induced vibration response and find out a method to mitigate such an excessive wind-induced vibration at the preliminary design stage. Recently, many studies have been conducted in using actuator control force based on the linear quadratic optimum control algorithm. It was accepted as a common knowledge that the performance of passive tuned mass damper(TMD) could increase by incorporating a feedback active control force in the design of TMD, which is called active tuned mass damper(ATMD). However, the fact that ATMD is superior to TMD to reduce wind-induced vibration of a tall building is still a question. The effectiveness of TMD for mitigating the along-wind vibration of a tall building was investigated. Optimum parameters of tuning frequency and damping ratio for TMD under a random load which has a white noise spectra were used. Fluctuating along-wind load acting on a tall building treated as a stationary Gaussian random process was simulated numerically using the along-wind load spectra. And using this simulated along-wind load, along-wind responses of a tall building with and without TMD were calculated and the effectiveness of TMD in mitigating the along-wind response of a tall building was found out.展开更多
文摘高层建筑作为应对城市人口和经济增长的重要手段,是世界性城市发展的必然趋势之一。高层建筑的空间分布与高度控制对城市景观有显著影响,是城市景观控制的重要方面。本文以伦敦市为例,总结了高层建筑控制相关政策的发展历程,并从区域控制、天际轮廓线和景观保护区三个方面详细介绍了高层建筑的控制内容和方法,同时以让·努维尔(Jean Nouvel)设计的新交易港一号(One New Change)商场为例进一步说明。最后,文章讨论了英国城市景观中的高层建筑控制对我国的启示。
文摘Multimodal control for seismic responses of tall buildings is performed by using MTMDs. Installation and main parameters of MTMDs are described, equations of motion of the coupled system of tall buildings and MTMDs are built under earthquake excitations, and parametrical optimization for multimodal control is carried out under excitations of harmonic ground motion. An 11 story frame building controlled by MTMDs is simulated under the excitation of El Centro earthquake (1940, NS), and its displacement response at the top floor in the case of multimodal control is reduced by 20% more than the case of single modal control. Some conclusions are given as the MTMDs is an effective, reliable and practical passive measurement for controlling seismic responses of tall buildings and the multimodal control has better adaptability and reliability by comparison with the single modal control.
基金Project(2011-0028567)supported by the National Research Foundation of Korea
文摘Most of modern tall buildings using lighter construction materials with high strength and less stiffness are more flexible, which occurs excessive wind-induced vibration, resulting in occupant discomfort and structural unsafety. It is necessary to predict wind-induced vibration response and find out a method to mitigate such an excessive wind-induced vibration at the preliminary design stage. Recently, many studies have been conducted in using actuator control force based on the linear quadratic optimum control algorithm. It was accepted as a common knowledge that the performance of passive tuned mass damper(TMD) could increase by incorporating a feedback active control force in the design of TMD, which is called active tuned mass damper(ATMD). However, the fact that ATMD is superior to TMD to reduce wind-induced vibration of a tall building is still a question. The effectiveness of TMD for mitigating the along-wind vibration of a tall building was investigated. Optimum parameters of tuning frequency and damping ratio for TMD under a random load which has a white noise spectra were used. Fluctuating along-wind load acting on a tall building treated as a stationary Gaussian random process was simulated numerically using the along-wind load spectra. And using this simulated along-wind load, along-wind responses of a tall building with and without TMD were calculated and the effectiveness of TMD in mitigating the along-wind response of a tall building was found out.
